The invention relates generally to the field of hydraulic circuits and, more particularly, to a gas/oil separator associated with a hydraulic reservoir to separate gas from the hydraulic fluid.
The presence of gas, such as air, in hydraulic fluid is known to cause problems in hydraulic-operated devices. The circuits for such hydraulically actuated devices typically include a hydraulic reservoir, as well as a pump for circulating the hydraulic fluid and hydraulic-operated components, such as actuators, within the circuit. Typical problems caused by the presence of a gas, such as air, are pump cavitation, slow or erratic response of the hydraulic components, and increase in the horsepower consumption within the circuits which results in higher operating temperatures for the fluid.
Of special concern is the removal of gas from a hydraulic fluid in hydraulic circuits located in a weight and/or space restricted vehicle, such as an airplane. One of the current techniques for removing gas from the hydraulic fluid in aircraft fluid circuits is to place an aspirator, which operates on the principles of the Bernoulli effect, in the hydraulic circuit at a location outside the hydraulic fluid reservoir. These aspirators mechanically remove air from the hydraulic fluid. However, due to the limited capacity of the aspirator, only a small amount of the supersaturated fluid can be deaerated at any given time. Additionally, aspirator devices require an external power source and contain moving parts (which thereby inherently decrease the reliability of the aspirator). They are orientation-sensitive and must be positioned in the hydraulic circuit at a location outside of the reservoir, thereby significantly increasing the size of the "envelope" of the hydraulic circuit.
A system is needed which can effectively separate gas from the hydraulic fluid circulating within a hydraulic circuit and which, at the same time, minimizes any increase in the size of the hydraulic circuit "envelope".